1. Field of the Invention
The present invention relates to a disk recording system for recording data subjected to error correction including interleaving on a disk in units containing a predetermined number of blocks, and relates in particular to such a disk recording system which ensures continuity of recorded data.
2. Description of Related Art
CD-R (Recordable) drives of the CD (Compact Disc) family are well known disk recording systems which record data on disks. A write-once media such as a CD-R which prohibit physical erasure of already recorded data have a problem that when data to be recorded becomes discontinuous regions used in the recording cannot be corrected by rewriting or re-use.
There is, therefore, a demand for a disk recording system that allows data to be continuously recorded on a disk without wasting medium regions used in the recording, even if the recording data becomes discontinuous.
In a packet write system which records data in packet units, it is possible to continuously record data without wasting medium regions used in the recording, even when the recording data becomes discontinuous. However, the packet write system requires as many as seven link blocks for connecting the packets and use of disk recording capacity in this manner is considered wasted.
However, by writing data at the interrupted data position on a disk so as to be continuous to the interrupted data, the packet write system can be eliminated and data recording which wastes no medium regions can be achieved.
Recording data for the CD system is subjected to CIRC (Cross Interleaved Reed-Solomon Code) error correction and has therefore been interleaved.
Since the interleave length reaches a maximum of 108 frames, this introduces the following problem. Namely, when recording data on a disk so as to be continuous to the interrupted data, the interleave length cannot be simultaneously secured at both the last block of the data received immediately before recording interruption and at the first block of the data received immediately after release of recording interruption.
The present invention was conceived in view of the foregoing problems and it is an object of the present invention to allow data recording on a disk without requiring formation of any link blocks as in the packet write system, while ensuring appropriate interleaving at the last block of data received immediately before recording interruption and at the first block of data received immediately after resumption of recording.
According to the present invention, when data recording is interrupted due to termination of data reception, specific data is generated by data generation means and is added to the last block of the data received immediately before the interruption so that the interleave length of the block can be secured. Thus, the data in the last block can be appropriately interleaved and modulated for recording on the disk. Further, according to the present invention, when data reception is resumed after the interruption of data recording, the same specific data as in the recording interruption is generated in said data generation means and is added to the first block of data received immediately after resumption of data reception so that the interleave length of the block can be secured. Thus, the data in the first block can be appropriately interleaved and modulated for recording on the disk.
In particular, new data to be recorded is synchronized with the data already recorded on the disk by a synchronizing device and is recorded at a recording start position detected by a recording start position detector. Accordingly, it is possible to continuously record new data at a position which is continuous to the terminal end of the already recorded data.